The Azimuth Project
Individual based ecology

Contents

Idea

Individual-based ecology (IBE) starts from the assumption that in essence an ecology consists of living interacting, independent individuals with their own growth, metabolism and reproduction. So while feeding to grow they also change their surroundings. They also individually adapt to the internal and external environment.

So that is one motive to make ecological models as interacting individuals with an objective to survive and pass their genes to the next generation.

Details

According to the book by Grimm and Railsback there are some ecological areas that have been modeled and researched with examples like:

  • Group behavior like flock-like behaviors.

  • Population dynamics among social animals,among marmots and birds, how they move and change habitats.

  • Movement and dispersal of trout and lynx.

  • Comparisons with classical ecological analytical models like logistic map and Lotka-Volterra.

  • Plant dynamics like forests.

  • Structure of ecosystems like beech forests.

Software

The IBE are similar to agent based modeling? and discrete event simulators which are also used to model complex systems?. For example some open source framework are Repast, based on Swarm which was developed at Santa Fe Institute.

Here is a list of many open source and commercial software frameworks at the swarm site

References

Abstract We use an individual-based simulation model to investigate factors influencing progress toward ecological speciation. We find that environmental differences can quickly lead to the evolution of substantial reproductive barriers between a population colonizing a new environment and the ancestral population in the old environment. Natural selection against immigrants and hybrids was a major contributor to this isolation, but the evolution of sexual preference was also important. Increasing dispersal had both positive and negative effects on population size in the new environment and had positive effects on natural selection against immigrants and hybrids. Genetic divergence at unlinked, neutral genetic markers was low, except when environmental differences were large and sexual preference was present. Our results highlight the importance of divergent selection and adaptive divergence for ecological speciation. At the same time, they reveal several interesting nonlinearities in interactions between environmental differences, sexual preference, dispersal and population size.

Abstract We analyze an interacting particle system with a Markov evolution of birth-and-death type. We have shown that a local competition mechanism (realized via a density dependent mortality) leads to a globally regular behavior of the population in course of the stochastic evolution.

category: ecology